Abstract: Antenna arrays that provide directive radiation over multiple frequencies, multiple polarizations, and/or operate in modes that reduce unnecessary radiation into a nearby human body. The arrays are particularly adapted for use with handheld wireless devices, such as smartphones, tablets, and cellular phones.

Abstract: Methods and apparatus for detecting body vital signs through the use of a Bioelectric Impedance Spectroscopy (BIS), either by (a) direct contact with the person (such as through one or more of their fingers) or (b) measurement of reflections from a field projected into the person's body. The techniques may be implemented using the projected capacitive touch array in a device such as the screen of a smartphone or tablet computer, or the touchpad of a laptop computer.

Abstract: A scanning optical device suitable for use as a camera or solar concentrator.

Abstract: A human safe wireless charging system using a circularly polarized source antenna that can radiate in either a hemispherical pattern or directional cardiod-like patterns at a 40-50, 150, or 200 MHz frequencies to a receiving loop antenna which is coupled to a parasitic receive element.

Abstract: We present several unique techniques for using touch sensor arrays to detect fingerprints and authenticate a user.

Abstract: A method for operating a two-dimensional touch array by providing virtual grid intersections. The techniques may be used to improve the array resolution. It may also be used to detect fingerprint ridge and valley detail even when the finger is not moving, and when the array node spacing is much greater than the ridge and valley spacing.

Abstract: A leaky travelling wave array of elements provide a broadband radio frequency antenna.

Abstract: A touch screen, now incorporated in most smart phones, presents an effective and transparent method to incorporate continuous active user verification schemes. The projected capacitive grid structure can be used to capture information, such as from the user's fingerprint. This information may be used to verify the user, or that a valid user currently has possession of the mobile device, even while the user is not consciously engaged in an active verification interface. Further processing, such as habitual gesture recognition, can augment the process.

Abstract: A touchscreen, now incorporated in most smartphones, tablets, laptops, and similar devices, presents an effective and transparent method to incorporate continuous active user verification schemes. The touchscreen element grid structure can be used to capture information, such as a set of one-dimensional time-varying signals produced as the user's finger moves past the grid intersections points. This information may be used to verify the user, or that a valid user currently has possession of the mobile device, even while the user is not consciously engaged in an active verification process. Further functions, such as habitual gesture recognition, can also be performed using the same grid outputs.

Abstract: A dielectric travelling wave antenna (DTWA) using a TEM mode transmission line and variable dielectric substrate.

Abstract: Techniques for implementing series-fed antenna arrays with a variable dielectric waveguide. In one implementation, coupling elements with optional controlled phase shifters are placed adjacent each radiating element of the array. To avoid frequency sensitivity of the resulting array, one or more waveguides have a variable propagation constant. The variable waveguide may use certain materials exhibiting this phenomenon, or may have configurable gaps between layers. Plated-through holes and pins can control the gaps; and/or a 2-D circular or a rectangular travelling wave array of scattering elements can be used as well.

Abstract: A prism coupled waveguide-fed solar collector array optimized for geometric fill factor. An integrated linear array of prisms is arranged with their input faces in a common plane. The exit faces of the prisms each feds a corresponding optical waveguide and detector.

Abstract: A rectifier comprising a metal-insulator-metal (MIM) structure. The insulator may be a native oxide with an adjacent layer of graphene. In one implementation, the rectifier is used in an electromagnetic energy collector consisting of a planar waveguide formed of multiple material layers having at least two different dielectric constants. MIM rectifiers are aligned with mirrors are formed within the waveguide core. In some arrangements, a plurality of MIM rectifiers are disposed in a column or 3D array beneath each mirror.

Abstract: Techniques for implementing series-fed antenna arrays with a variable dielectric waveguide. In one implementation, coupling elements with optional controlled phase shifters are placed adjacent each radiating element of the array. To avoid frequency sensitivity of the resulting array, one or more waveguides have a variable propagation constant. The variable waveguide may use certain materials exhibiting this phenomenon, or may have configurable gaps between layers. Plated-through holes and pins can control the gaps; and/or a 2-D circular or a rectangular travelling wave array of scattering elements can be used as well.

Abstract: A touch screen, now incorporated in most smart phones, presents an effective and transparent method to incorporate continuous active user verification schemes. The projected capacitive grid structure can be used to capture information, such as from the user's fingerprint. This information may be used to verify the user, or that a valid user currently has possession of the mobile device, even while the user is not consciously engaged in an active verification interface. Further processing, such as habitual gesture recognition, can augment the process.

Abstract: A touch screen, now incorporated in most smart phones, presents an effective and transparent method to incorporate continuous active user verification schemes. The projected capacitive grid structure can be used to capture enough information to verify that a valid user currently has possession of the mobile device, even while the user is not consciously engaged in an active verification interface. Further processing, such as habitual gesture recognition, can augment the process.

Abstract: A planar fixed area thin film antenna-coupled metal-insulator-metal (MIM) rectifier of arbitray metal with a native nickel oxide insulator. Devices can be designed for millimeter wave, IR, NIR and visible wavelengths.

Abstract: The use of rectennas, or antenna-coupled rectifiers, using metal-insulator-metal tunnel diodes as rectifiers for energy conversion has been explored with more fervor recently, given the advances in nanotechnology fabrication and increased resolution of features. Some have made these devices from symmetric metals (e.g. Ni—NiO—Ni) and asymmetric metals (e.g. Al—AlOx/Pt), and have used deposited oxides as well as native oxides. One key to obtaining a highly asymmetric device with efficient current generation needed for high conversion efficiency is to instead use dissimilar metals and a thin reproducible oxide. The described method allows for a thin, reproducible native oxide of nickel be integrated with any antenna metal to overcome oxide surface roughness problems that typically hamper the practicality of these devices.

Abstract: A stacked bow tie antenna array structure is placed within, for example a rectangular reflector. Spaces between the bow tie elements and the reflector are filled with close spaced conductive plates.

Abstract: A multi-band whip antenna having a 30 MHz to 2 GHz bandwidth and an L-band dipole has its coverage extended up to 6 GHz by eliminating nulls and reducing VSWR problems that are cured through the utilization of a sleeve over the feedpoint of the L-band antenna. Chokes in the form of sleeves are provided at either end of the L-band dipole to shorten the L-band antenna for preventing reverse polarity currents at the L-band antenna feedpoint, with the antenna further including the use of double shielded meanderline to provide improved performance between 410-512 MHz and in which a capacitance sleeve is added at the bottom of the L-band antenna to effectively elongate the antenna below the L-band to permit operation below 700 MHz.